Bloated star swallows Jupiter-sized planet – 5/4/2023 – Science

In a glimpse of the grim fate that awaits Earth, scientists have observed for the first time a star, bloated in its old age, gobbling up a Jupiter-like planet and then spewing some material into space in an energetic belch.

Researchers said on Wednesday the star was in the early stages of what is called a red giant phase at the end of its lifespan as it has run out of hydrogen fuel in its core and its dimensions have begun to expand. As the star grew, its surface reached the orbit of the doomed planet, resulting in chaos.

The star, which started out similar to our Sun in size and composition, is located in our galaxy, the Milky Way, about 12,000 light-years from Earth, in the constellation of Aquila. A light year is the distance that light travels in one year, 9.5 trillion km. The star is about 10 billion years old, twice as old as the sun.

Red giant stars can swell up to a hundred times their original diameter, engulfing any planet in their path. Scientists have previously observed such stellar expansion, but not planetary engulfment.

Mercury, Venus and ultimately Earth, the three innermost planets in our Solar System, will meet this fate as the Sun passes through its red giant phase in about 5 billion years, according to Kishalay De, post -doctoral fellow at MIT’s Kavli Institute for Astrophysics and Space Research and lead author of the study published in the journal Nature.

The planet in this research was a type called a “hot Jupiter” – a gas giant similar to the biggest world in our Solar System, but orbiting much closer to its star. This planet, perhaps a few times the size of Jupiter, orbited its star in less than a day at a closer distance than Mercury, our innermost planet, orbits the Sun.

“The planet began to slip through the star’s atmosphere like a satellite falling into Earth’s atmosphere. The deeper the planet fell into the star’s atmosphere, the denser the environment and the faster it was dragged inward,” said co-author of the study, Morgan MacLeod, a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics.

The researchers haven’t detected any other planets orbiting this star, but they don’t rule it out.
“It is humbling to think of our own planet meeting a similar fate, let alone realizing that we are too small to make the Sun experience an explosion like this one. When the Earth is eventually swallowed up, the Sun will hardly notice,” MacLeod said.